Biomaterial occluder delivery mechanism

ABSTRACT

A medical device including a removable frame and biomaterial cover, methods of assembling and using the same, and a delivery system including the same are described herein. The medical device includes a frame having proximal and distal ends, the frame including a proximal disc at the proximal end, a distal disc at the distal end, and a connecting segment having a proximal end and a distal end connecting the proximal and distal discs. Each of the proximal and distal discs includes a respective plurality of prongs and has a maximum cross-sectional dimension larger than the connecting segment. The medical device further includes at least one biomaterial cover including an outer section and an inner section defining a cavity therebetween, wherein at least one of the proximal and distal discs of the frame is positioned in the cavity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalPatent Application No. 63/028,423, filed May 21, 2020, the entirecontents and disclosure of which are hereby incorporated by referenceherein.

BACKGROUND OF THE DISCLOSURE A. Field of Disclosure

The present disclosure relates generally to medical devices that areused in the human body. In particular, the present disclosure isdirected to embodiments of an occlusion device that enables removal of adevice frame from the occlusion device after the occlusion device isdeployed in the human body. More specifically, the present disclosure isdirected to an occlusion device with a temporary device frame thatpromotes native tissue growth while maintaining the fundamental functionand effectiveness of an occluder. The embodiments and methods disclosedherein enable the removal of the device frame and the promotion ofnative tissue growth by the incorporation of a biomaterial cover over atleast a portion of the device frame.

B. Background

An occluder is a medical device used to treat (e.g., occlude) tissue ata target site within the human body, such as an abnormality, a vessel,an organ, an opening, a chamber, a channel, a hole, a cavity, a lumen,or the like. For example, an occluder may be used in trans-cathetersecundum atrial septal defect closures. Secundum atrial septal defectsare common congenital heart defects that allow blood to flow between theleft and right atria of the heart, decreasing cardiac output. Occludersmay be employed to block this blood flow.

At least some known occluders may be formed from shape-formed braidednitinol that is permanently implanted in the target site of the humanbody. Accordingly, the presence of the occluder creates a permanentforeign object within the patient. The presence of a foreign object canpresent adverse side effects, such as erosion of tissue around theimplanted device, development of arrhythmia, and, where a patient maydevelop a nickel allergy, adverse allergic effects.

Accordingly, it would be desirable to reduce the presence of a permanentforeign object within the body of the patient as much as possible, whilemaintaining the fundamental function and effectiveness of an occluder.

SUMMARY OF THE DISCLOSURE

The present disclosure generally relates to medical devices and methodsof manufacturing and use thereof, which facilitate the minimization of apermanent foreign object at a target site within a patient's body whilemaintaining the fundamental function and effectiveness of the medicaldevice (e.g., an occlusion device).

In one embodiment, the present disclosure is directed to a medicaldevice for treating a target site. The medical device includes a framehaving proximal and distal ends. The frame includes a proximal disc atthe proximal end, a distal disc at the distal end, and a connectingsegment having a proximal end and a distal end connecting the proximaland distal discs. Each of the proximal and distal discs includes arespective plurality of prongs and has a maximum cross-sectionaldimension larger than the connecting segment. The medical device alsoincludes at least one biomaterial cover, the biomaterial cover includingan outer section and an inner section defining a cavity therebetween,wherein at least one of the proximal and distal discs of the frame ispositioned in the cavity.

In another embodiment, a retrieval system for retrieving a medicaldevice from a target site is provided. The retrieval system includes amedical device and a retrieval device. The medical device includes aframe having proximal and distal ends. The frame includes a proximaldisc at the proximal end, a distal disc at the distal end, and aconnecting segment having a proximal end and a distal end connecting theproximal and distal discs. Each of the proximal and distal discsincludes a respective plurality of prongs and has a maximumcross-sectional dimension larger than the connecting segment. Themedical device also includes at least one biomaterial cover, thebiomaterial cover including an outer section and an inner sectiondefining a cavity therebetween, wherein at least one of the proximal anddistal discs of the frame is positioned in the cavity. The retrievaldevice includes a retrieval catheter, a recapture cable within theretrieval catheter and translatable with respect to the retrievalcatheter, and a coupling member configured to couple the medical deviceto the recapture cable for facilitating withdrawal of the frame from theat least one biomaterial cover after the medical device is fullydeployed at the target site.

In a further embodiment, a method of recapturing a device frame deployedat a target site is provided. The method includes locating an expandedmedical device at the target site. The medical device includes a framehaving proximal and distal ends. The frame includes a proximal disc atthe proximal end, a distal disc at the distal end, and a connectingsegment having a proximal end and a distal end connecting the proximaland distal discs. Each of the proximal and distal discs includes arespective plurality of prongs and has a maximum cross-sectionaldimension larger than the connecting segment. The medical device alsoincludes at least one biomaterial cover, the biomaterial cover includingan outer section and an inner section defining a cavity therebetween,wherein at least one of the proximal and distal discs of the frame ispositioned in the cavity. The method also includes coupling a cable tothe frame of the medical device, rotating the cable to constrict theplurality of prongs of the frame, and withdrawing the frame from the atleast one biomaterial cover at the target site.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a known medical device;

FIG. 2A is an exemplary embodiment of a delivery system including adelivery device and a medical device in accordance with the presentdisclosure;

FIGS. 2B and 2C illustrate delivery of the medical device using thedelivery system shown in FIG. 2A;

FIG. 3 illustrates a side sectional view of a first exemplary embodimentof the medical device including a frame and a biomaterial cover, inaccordance with the present disclosure;

FIG. 4 illustrates a top sectional view of the medical device shown inFIG. 3 ;

FIG. 5 illustrates a side sectional view of a second embodiment of themedical device in accordance with the present disclosure.

FIG. 6 illustrates a top sectional view of a third embodiment of themedical device in accordance with the present disclosure;

FIGS. 7A-7C illustrate one exemplary embodiment of recapture of theframe of the medical device in accordance with the present disclosure;

FIG. 8 is a flow diagram of a method of recapturing and removing a framefrom a deployed medical device, in accordance with the presentdisclosure;

FIG. 9 illustrates one exemplary embodiment of delivery of the medicaldevice to a target site, in accordance with the present disclosure; and

FIGS. 10A and 10B illustrate another exemplary embodiment of recaptureof the frame of the medical device.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings. It is understood that thatFigures are not necessarily to scale.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure relates generally to medical devices that areused in the human body. Specifically, the present disclosure providesmedical devices including occlusion devices having a biomaterial coverand a frame that is removable from the biomaterial cover, and from thepatient's body, after the occlusion device has been deployed within thebody at a target site. The biomaterial cover promotes tissue ingrowthsuch that, after a period of time, the biomaterial cover and tissueprovide sufficient occlusion of the target site. Thereafter, the framecan be withdrawn from the at least one biomaterial cover withoutdetriment to the occlusive effects of the occlusion device. In oneexemplary embodiment, the frame includes a plurality of prongs, whichenables de-coupling of the frame from the biomaterial cover as describedherein.

Accordingly, the occlusion devices of the present disclosure promotenative tissue growth to achieve the fundamental function andeffectiveness of the occluder, which enables the removal of the framefrom the human body, to reduce or eliminate the above-described adverseeffects of foreign objects within the patient's body.

The disclosed embodiments may lead to more consistent and improvedpatient outcomes. It is contemplated, however, that the describedfeatures and methods of the present disclosure as described herein maybe incorporated into any number of systems as would be appreciated byone of ordinary skill in the art based on the disclosure herein.

It is understood that the use of the term “target site” is not meant tobe limiting, as the medical device may be configured to treat any targetsite, such as an abnormality, a vessel, an organ, an opening, a chamber,a channel, a hole, a cavity, or the like, located anywhere in the body.The term “vascular abnormality,” as used herein is not meant to belimiting, as the medical device may be configured to bridge or otherwisesupport a variety of vascular abnormalities. For example, the vascularabnormality could be any abnormality that affects the shape of thenative lumen, such as an atrial septal defect, an LAA, a lesion, avessel dissection, or a tumor. Embodiments of the medical device may beuseful, for example, for occluding an LAA, ASD, VSD, or PDA, as notedabove. Furthermore, the term “lumen” is also not meant to be limiting,as the vascular abnormality may reside in a variety of locations withinthe vasculature, such as a vessel, an artery, a vein, a passageway, anorgan, a cavity, or the like. For ease of explanation, the examples usedherein refer to the occlusion of a septal defect (e.g., an atrial septaldefect or ASD).

As used herein, the term “proximal” refers to a part of the medicaldevice or the delivery device that is closest to the operator, and theterm “distal” refers to a part of the medical device or the deliverydevice that is farther from the operator at any given time as themedical device is being delivered through the delivery device. Inaddition, the terms “deployed” and “implanted” may be usedinterchangeably herein.

Some embodiments of the present disclosure provide an improvedpercutaneous catheter directed intravascular occlusion device for use inthe vasculature in patients' bodies, such as blood vessels, channels,lumens, a hole through tissue, cavities, and the like, such as an atrialseptal defect. Other physiologic conditions in the body occur where itis also desirous to occlude a vessel or other passageway to preventblood flow into or therethrough. These device embodiments may be usedanywhere in the vasculature where the anatomical conditions areappropriate for the design.

The medical device may include one or more discs that are at leastpartially covered by a biomaterial cover that acts as an occlusivematerial, while promoting native issue growth, which is configured toocclude or substantially preclude the flow of blood. Most commonly,blood flow may be occluded immediately. However, it is contemplatedthat, in some cases, some blood flow may occur. Accordingly, as usedherein, “substantially preclude” or, likewise, “substantially occludedblood flow” shall mean, functionally, that minimal or trace blood flowaround or through the medical device may occur for a short time, butthat the body's tissue growth onto the biomaterial cover results in fullocclusion after this initial time period.

The present disclosure now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the disclosure are shown. Indeed, this disclosure may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

In at least some conventional or known medical devices used for theocclusion of abnormalities, such as a medical device 50 shown in FIG. 1, a metal frame 52 provides the occlusive property. The occlusiveproperties of these known devices arise from the facilitation ofthrombosis. Metal frame 52 is formed from shape-memory material, mostcommonly Nitinol, that uses a single-layer, seventy-two wire braiddesign. As described above, when these medical devices are utilized toocclude blood flow through an abnormality, metal frame 52 becomes apermanent foreign object within the patient's body. The presence ofmetal frame 52 within the patient's body can potentially lead to adverseside effects such as erosion or development of a nickel allergy.

The medical devices of the present disclosure, which includes abiomaterial cover and a removable frame, minimize these disadvantages ofknown medical devices.

Turning now to FIG. 2A, a schematic diagram of a delivery system 100 isshown. Delivery system 100 includes a delivery device 102 including acatheter 104 and a coupling member 106 configured to couple a distal endof a delivery cable 107 to a connecting member 108 of a medical device110 for facilitating the deployment of medical device 110 at a targetsite. Medical device 110 is deployed to treat the target site, and, inthe example embodiment, is an occlusion device (“occluder”).

FIGS. 3 and 4 illustrate a first exemplary embodiment of medical device110. Specifically, FIG. 3 is a side sectional view of medical device110, and FIG. 4 is a top sectional view of medical device 110. As shownin FIGS. 3 and 4 , medical device 110 includes a device frame 112 and atleast one biomaterial cover 114. Device frame 112 includes a proximaldisc 116 and a distal disc 118. Proximal disc 116 at least partiallydefines a proximal end 120 of medical device 110 and frame 112, anddistal disc 118 at least partially defines a distal end 122 of medicaldevice 110 and frame 112.

Proximal and distal discs 116, 118 are joined together by a connectingsegment 124. In the exemplary embodiment, connecting segment 124 iscoaxial with proximal and distal discs 116, 118. In other embodiments,connecting segment 124 is other than coaxial with (e.g., off-center withrespect to) proximal disc 116 and/or distal disc 118. In the exemplaryembodiment, connecting member 108 is coupled to and extends from aproximal end of connecting segment 124. Alternatively, connecting member108 may be coupled to and extend from proximal disc 116.

Moreover, in the exemplary embodiment, frame 112 is a unitary component,and proximal disc 116, distal disc 118, and connecting segment 124 areintegrally formed with one another. Alternatively, proximal disc 116,distal disc 118, and connecting segment 124 are separately formed andare coupled together to form frame 112.

As shown in FIG. 4 , distal disc 118 includes a plurality of prongs 126that define distal disc 118. Although not shown in FIG. 4 , proximaldisc 116 is substantially the same as distal disc 118—that is, thedescription of distal disc 118 also applies to proximal disc 116.

Each of prongs 126 is arcuate in shape and extends radially outwardly ina first direction 128 that is defined from connecting segment 124 to afree end 130 of the corresponding prong 126. For example, in FIG. 4 ,first direction 128 is a generally counter-clockwise direction. Itshould be readily understood that first direction 128 may be clockwisein any other embodiment. This shape or configuration of prongs 126 isgenerally referred to as a “bent star” shape or configuration, referringto the overall “star” configuration of the prongs 126 within one ofdiscs 116, 118 and the bent (e.g., curved or coiled) free ends 130thereof. Each prong 126 is substantially similar to each other prong 126in distal disc 118.

It is contemplated that the plurality of prongs 126 may be arranged inmany different configurations. The configuration is limited only by theability to retract the prongs from the biomaterial cover 114 tode-couple or withdraw the prongs 126 from biomaterial cover 114 andremove or withdraw frame 112 from biomaterial cover 114 (and, therefore,remove or withdraw frame 112 from medical device 110 at the targetsite), as described further herein.

In one embodiment, device frame 112 is formed from a shape-memorymaterial. One particular shape memory material that may be used isNitinol. Nitinol alloys are highly elastic and are said to be“superelastic,” or “pseudoelastic.” This elasticity may allow medicaldevice 110 to be resilient and return to a preset, expandedconfiguration for deployment following passage in a distorted formthrough delivery catheter 104. Further examples of materials andmanufacturing methods for medical devices with shape memory propertiesare provided in U.S. Publication No. 2007/0265656 titled “Multi-layerBraided Structures for Occluding Vascular Defects” and filed on Jun. 21,2007, which is incorporated by reference herein in its entirety.

It is also understood that device frame 112 may be formed from variousmaterials other than Nitinol that have elastic properties, such asstainless steel, trade named alloys such as Elgiloy®, or Hastalloy,Phynox®, MP35N, CoCrMo alloys, metal, polymers, or a mixture of metal(s)and polymer(s). Suitable polymers may include PET (Dacron™), polyester,polypropylene, polyethylene, HDPE, Pebax, nylon, polyurethane, silicone,PTFE, polyolefins and ePTFE. Additionally, it is contemplated that thedevice frame may comprise any material that has the desired elasticproperties to ensure that the device may be deployed, function as anoccluder, and be recaptured in a manner disclosed within thisapplication.

Biomaterial cover 114, in the exemplary embodiment, covers or surroundsat least a portion of frame 112. For example, biomaterial cover 114 atleast partially surrounds proximal disc 116 and/or distal disc 118. Inthe exemplary embodiment, biomaterial cover 114 defines one or morecavities in which proximal disc 116 and/or distal disc 118 arepositioned. In the embodiment shown in FIG. 3 , biomaterial cover 114 istwo separate components, such as a first or proximal cover 132 and asecond or distal cover 134. Proximal cover 132 at least partiallysurrounds proximal disc 116, and engages with or is coupled to frame 112at least at proximal disc 116. Proximal cover 132 includes a first orouter section 136 and a second or inner section 138 that together definea cavity 140 in which proximal disc 116 is positioned. First section 136and/or second section 138 engages with or is coupled to proximal disc116. In some embodiments, second section 138 may be further removablycoupled to and/or engaged with connecting segment 124 (e.g., viabioabsorbable sutures).

Distal cover 134 at least partially surrounds distal disc 118, andengages with or is coupled to frame 112 at least at distal disc 118.Distal cover 134 also includes a first section 136 and a second section138 that also define a cavity 140. Distal disc 118 is positioned withincavity 140. First section 136 and/or second section 138 is coupled todistal disc 118. In some embodiments, second section 138 may be furtherremovably coupled to and/or engaged with connecting segment 124 (e.g.,via bioabsorbable sutures). It should be readily understood that, insome embodiments, biomaterial cover 114 includes only one of proximalcover 132 and distal cover 134.

In the exemplary embodiment, each respective first section 136 andsecond section 138 are coupled together and to the respective disc 116,118 of frame 112 by bioabsorbable sutures 142. As shown in FIG. 4 ,bioabsorbable sutures 142 are specifically arranged to create arespective pocket 144 around each prong 126, to improve retention ofprongs 126 within biomaterial cover 114. As shown in FIG. 3 , thesebioabsorbable sutures 142 extend through both the first and secondsection 136, 138 (of the respective disc) to form pockets 144.Bioabsorbable sutures 142 may also be used to couple respective firstand second sections 136, 138 together. For example, bioabsorbablesutures 142 are sewn around a circumference of first and second sections136, 138. Alternatively, where first and second sections 136, 138 areintegrally formed (i.e., proximal cover 132 is a unitary componentand/or distal cover 134 is a unitary component), bioabsorbable sutures142 are not needed to couple respective first and second sections 136,138 together. Although sutures 142 are referred to herein asbioabsorbable, it should be understood that, in some embodiments, suture142 may not be bioabsorabable and may be formed from any suitable suturematerial.

In some alternative embodiments, as shown in FIG. 5 , biomaterial cover114 may be a single component that substantially covers an entirety offrame 112 (e.g., both proximal and distal discs 116, 118 and connectingsegment 124, but with an opening remaining at a proximal section thereoffor subsequent withdrawal of frame 112). In this embodiment, biomaterialcover 114 includes a central section 146 coupled to and extendingbetween second sections 138 of proximal and distal covers 132, 134.Biomaterial cover 114 may be a unitary component (e.g., proximal cover132, distal cover 134, and central section 146 may be integrally formedwith one another), or proximal cover 132, distal cover 134, and centralsection 146 may be separately formed and then coupled together to formbiomaterial cover 114.

In one embodiment, biomaterial cover 114 is formed from a bioabsorbablepolymer. The bioabsorbable polymer may include, for example,Poly-L-lactic acid (PLLA), Poly(glycolic acid) (PGA), Copolyesters ofpoly(e-caprolactone) (PCL), Trimethylene carbonate (TMC),Poly(d-diozanone) (PPDO), and combinations of various polymers.Additionally or alternatively, the biomaterial cover is formed fromanother polymer. The polymer may include, for example, PET (Dacron™),polyester, polypropylene, polyethylene, HDPE, Pebax, nylon, PTFE,polyolefins and ePTFE.

In other embodiments, biomaterial cover 114 may be formed from a tissue,such as pericardial tissues. The tissues may be derived from, forexample, porcine, bovine, equine, and/or collagen matrices.

FIG. 6 illustrates another exemplary embodiment of medical device 110including an alternative configuration of the plurality of prongs 126.In this embodiment, each prong 126 is arcuate and extends radiallyoutwardly from connecting segment 124 in first direction 128, and theprong 126 also includes a helical or coiled free end 130 that completesat least one 360° rotation to further reduce the risk of free ends 130puncturing biomaterial cover 114. Moreover, biomaterial cover 114further includes a plurality of circular sewn pockets 148. Each coiledfree end 130 of a prong 126 extends about a respective circular pocket148. The 360° rotation about the respective circular pocket 148 mayimprove retention of the prong 126 within biomaterial cover 114, whilestill allowing for de-coupling and retraction of the prong 126 frombiomaterial cover 114.

In the exemplary embodiment, to form medical device 110, proximal disc116 and/or distal disc 118 is enclosed by a first section 136 and asecond section 138 of biomaterial cover 114. Bioabsorbable sutures 142are then applied through first section(s) 136 and second section(s) 138to form pockets 144 that secure prongs 126 inside biomaterial cover 114.

In operation, as shown in FIG. 2B, medical device 110 is advancedtowards the target site within catheter 104 of delivery device 102.Proximal and distal discs 116, 118 are folded or compressed withincatheter 104 during delivery. Once the target site has been reached,medical device 110 is deployed from catheter 104 into the abnormality tobe occluded using delivery cable 107, as shown in FIG. 2C. Specifically,catheter 104 is positioned within or adjacent to the target site, andmedical device 110 is distally advanced until distal disc 118 isreleased from catheter 104. As described elsewhere herein, the shapememory and/or elastic material defining frame 112 causes distal disc 118to unfold or expand to its expanded form, on a distal side of the targetsite. Thereafter, catheter 104 is retracted proximally to releaseconnecting segment 124 and proximal disc 116 from catheter 104. Proximaldisc 116 unfolds or expands to its expanded form, on a proximal side ofthe target site.

When the placement of medical device 110 has been assessed and confirmed(e.g., by a physician), coupling member 106 of delivery device 102 isdisconnected from connecting member 108 of medical device 110. As shownin FIG. 9 , in some embodiments, connecting member 108 includes internalthreads 160 configured to mate with external threads 162 of couplingmember 106. In such cases, disconnecting coupling member 106 fromconnecting member 108 includes rotating delivery cable 107 in arotational direction opposite to the direction of mated threads 160,162. Thereafter, medical device 110 is considered fully deployed.

According to the present disclosure, medical device 110 is designed suchthat frame 112 can be recaptured and withdrawn or removed from medicaldevice 110, after medical device 110 has been deployed at the targetsite. In at least some embodiments, device frame 112 cannot berecaptured for some period of time, or until a sufficient amount ofendothelialization has occurred around biomaterial cover 114. The amountof time required for sufficient endothelialization to occur may dependon a number of factors, for example, the material used for biomaterialcover 114 or the target site at which medical device 110 is deployed. Aphysician may determine the appropriate time for removal of device frame112. For instance, the physician may determine there is a medical reasonfor frame 112 to be removed (e.g., a need to intervene again in the samearea to, for example, implant a mitral valve, conduct cardiac mapping,or implant an LAA occluder), and, after observing the amount ofendothelialization that has taken place to confirm tissue ingrowth issufficient to maintain occlusion of the target site, the physician mayremove frame 112 at such a time. In at least some embodiments, theremoval can occur after at least about 30-90 days after deployment andimplantation of medical device 110.

To recapture and remove frame 112, an implanted medical device 110(i.e., a medical device 110 that is currently in place at a target site)must be located. In some embodiments, confirmation may be made that asufficient amount of endothelialization has taken place, specifically,that the amount of tissue ingrowth is sufficient to provide an occlusiveeffect.

With reference to FIGS. 7A-7C as well as FIGS. 10A and 10B, in someembodiments, a recapture or retrieval system 700 is employed torecapture and withdraw or remove frame 112 from biomaterial cover 114 ofthe implanted medical device 110. In some instances, recapture system700 includes one more elements in common with delivery system 100, suchas delivery device 102 and/or delivery catheter 104. In other instances,recapture system 700 is wholly separate from delivery system 100.Accordingly, reference is made herein to a retrieval device 702 and aretrieval catheter (also referred to as a retrieval sheath) 704 ofrecapture system 700, regardless of their similarity with components ofdelivery system 100.

Recapture system 700 includes a recapture cable 707 that is advanced tothe target site at which medical device 110 was previously deployed.Recapture cable 707 includes a coupling member 706 at the distal endthereof. Coupling member 706 is coupled to proximal end 120 of frame 112(e.g., to connecting member 108). To retract prongs 126 from biomaterialcover 114, in some exemplary embodiments, frame 112 is rotated in asecond direction 150 (see FIG. 4 ) opposite to first direction 128. Thisrotation, in second direction 150, causes prongs 126 of proximal anddistal discs 116, 118 to be rotated opposite to their rotational shapeand, therefore, rotated out of their original expanded shape, to retractor withdraw prongs 126 from pockets 144. Thereby, frame 112 is“de-coupled” from biomaterial cover 114.

Notably, in some embodiments, depending on the shape of frame 112 and/orprongs 126 (e.g., the thickness, stiffness, or shape of prongs 126),frame 112 does not need to be rotated to de-couple frame 112 frombiomaterial cover 114. In such embodiments, frame 112 may be de-coupledfrom biomaterial cover 114 by applying only a proximally oriented forceto frame 112.

As frame 112 is being or has been de-coupled from biomaterial cover 114,frame 112 can be withdrawn from biomaterial cover 114 and, therefore,medical device 110 at the target site, leaving only biomaterial cover114 in place to provide the necessary occlusion of the target site.

In some embodiments, as shown in FIGS. 7A-7C, coupling member 706 isembodied as a loop or snare, which is advanced distally from retrievalcatheter 704 towards connecting member 108 of frame 112 (see FIG. 7A).Coupling member 706 is attached to connecting member 108 by loopingcoupling member 706 around connecting member 108 (see FIG. 7B). Oncecoupling member 706 has been looped around connecting member 108, thesnare is retracted into retrieval catheter 704 (see FIG. 7C) and/orretrieval catheter 704 is advanced distally until connecting member 108is secured within retrieval catheter 704 or a docking cap 754. Morespecifically, a distal end 752 of retrieval sheath 704 and/or ofrecapture cable 707 is fitted with a docking cap 754 to secureconnecting member 108 as frame 112 is withdrawn from biomaterial cover114. Retrieval catheter 704 or docking cap 754 may be advanced intoengagement with medical device 110 (e.g., proximal disc 116) to supportbiomaterial cover 114 while retracting frame 112 therefrom, to improveretention of biomaterial cover 114 within the target site duringwithdrawal of frame 112.

In one embodiment, as shown in greater detail in FIG. 10A, docking cap754 and connecting member 108 have complementary shapes. For example,docking cap 754 has a non-circular shape that is complementary to ashape of connecting member 108, such that docking cap 754 is able totransfer rotational forces to connecting member 108. Although thesecomplementary shapes are depicted as generally triangular in FIGS. 10Aand 10B, it should be readily understood that various other regular andirregular non-circular shapes may be implemented (e.g., oval,rectangular, star-shaped, hexagonal, etc.). Additionally oralternatively, connecting member 108 may have a shape that is generallycircular but that includes one or more indentations, extensions, and thelike, such that the complementary shape of docking cap 754 may suitablyimpart rotational forces thereto. Once connecting member 108 has beensecured within docking cap 754, connecting member 108 (and, thereby,frame 112) is rotated (via rotational forces from docking cap 154) insecond direction 150 to de-couple and withdraw frame 112 frombiomaterial cover 114, as described above. In some embodiments, as shownin FIG. 10B, this rotational force may cause frame 112 to twist uponitself into a reduced profile or configuration for retraction intoretrieval catheter 704. In other embodiments, rotation of frame 112de-couples frame 112 from biomaterial cover 114, and force applied bythe distal end of retrieval catheter 704, as frame 112 is pulledproximally thereagainst, forces frame 112 into a reduced configurationfor retraction of frame 112 into catheter 704.

In other embodiments, although not shown, a loop or snare may be coupledto connecting member 108, and coupling member 106 may engage the loop orsnare. Moreover, in some embodiments, for example, where connectingmember 108 has a small diameter, retrieval catheter 704 does not includea docking cap, and frame 112 is retracted fully into retrieval catheter704 during withdrawal. In still other embodiments, coupling member 706includes more than one hoop or snare that are deployed simultaneously toengage connecting member 108.

Turning now to FIG. 8 a flow diagram of a method 800 for recapturing adevice frame from a medical device deployed at a target site in asubject is illustrated, according to one embodiment.

Method 800 includes locating 802 an expanded medical device (e.g.,medical device 110, shown in FIG. 2 ) at the target site. As describedherein, the medical device includes a frame having proximal and distalends, the frame including a proximal disc at the distal end, a distaldisc at the distal end, and a connecting segment having a proximal endand a distal end connecting the proximal and distal discs. Each of theproximal and distal discs includes a respective plurality of prongs, andeach of the proximal and distal discs have a maximum cross-sectionaldimension larger than the connecting segment. The medical device alsoincludes at least one biomaterial cover, the biomaterial cover includingan outer section and an inner section defining a cavity therebetween,wherein at least one of the proximal and distal discs of the frame ispositioned in the cavity.

Method 800 also includes coupling 804 a cable (e.g., recapture cable707, shown in FIG. 7A) to the frame of the medical device, rotating 806the cable to constrict the plurality of prongs of the frame (e.g., tode-couple the frame from the at least one biomaterial cover), andretracting 808 the frame from the biomaterial cover of the medicaldevice at the target site, to capture the plurality of prongs into theretrieval sheath.

Method 800 may include additional, alternative, and/or fewer steps,including those described herein. For example, in some embodiments,coupling 804 includes attaching a coupling member at a distal end of thecable to a connecting member at a proximal end of the frame. In somesuch embodiments, the attaching includes looping the coupling memberaround the connecting member (e.g., where the coupling member isembodied as a loop or snare). Moreover, in certain embodiments, method800 does not include rotating 806 (e.g., in embodiments in which theframe does not need to be rotated to de-couple the frame from thebiomaterial cover).

In some embodiments, each of the plurality of prongs are curved into abent star configuration in which each prong of the plurality of prongsextends radially outwardly from the connecting segment and has a radiusof curvature in a first direction defined between the connecting segmentand a corresponding free end of the corresponding prong. In some suchembodiments, rotating 806 includes rotating the cable in a seconddirection opposite to the first direction to de-couple the plurality ofprongs from the at least one biomaterial cover.

While embodiments of the present disclosure have been described, itshould be understood that various changes, adaptations and modificationsmay be made therein without departing from the spirit of the disclosureand the scope of the appended claims. Further, all directionalreferences (e.g., upper, lower, upward, downward, left, right, leftward,rightward, top, bottom, above, below, vertical, horizontal, clockwise,and counterclockwise) are only used for identification purposes to aidthe reader's understanding of the present disclosure, and do not createlimitations, particularly as to the position, orientation, or use of thedisclosure. It is intended that all matter contained in the abovedescription or shown in the accompanying drawings shall be interpretedas illustrative only and not limiting. Changes in detail or structuremay be made without departing from the spirit of the disclosure asdefined in the appended claims.

Many modifications and other embodiments of the disclosure set forthherein will come to mind to one skilled in the art to which thisdisclosure pertains having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the disclosure is not to be limited to the specificembodiments described and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

What is claimed is:
 1. A medical device for treating a target sitecomprising: a frame having proximal and distal ends, the framecomprising a proximal disc at the proximal end, a distal disc at thedistal end, and a connecting segment having a proximal end and a distalend connecting the proximal and distal discs, wherein each of theproximal and distal discs include a respective plurality of prongshaving a curvature in a first direction, each of the proximal and distaldiscs having a maximum cross-sectional dimension larger than theconnecting segment; and at least one biomaterial cover, the at least onebiomaterial cover comprising an outer section and an inner sectiondefining a cavity therebetween, wherein at least one of the proximal anddistal discs of the frame is positioned in the cavity, the at least onebiomaterial cover further comprising a plurality of pocketscorresponding to the plurality of prongs, wherein the plurality ofpockets are formed by one or more sutures wherein the plurality ofprongs enable (1) de-coupling of the frame from the at least onebiomaterial cover when the plurality of prongs are withdrawn from theplurality of pockets of the at least one biomaterial cover by rotationof the plurality of prongs in a second direction opposite the firstdirection after deployment of the medical device and endothelizationover the medical device at the target side (2) withdrawal of the framefrom the target site.
 2. The medical device of claim 1, wherein theframe comprises a shape-memory material.
 3. The medical device of claim2, wherein the shape-memory material comprises a material including atleast one of nitinol and a polymeric material.
 4. The medical device ofclaim 1, wherein a proximal end of the connecting segment comprises aconnecting member configured to couple the medical device to a retrievaldevice for retrieval of the medical device after the medical device hasbeen deployed at the target site.
 5. The medical device of claim 4,wherein the connecting member has a non-circular shape complementary toa shape of a docking cap on the retrieval device.
 6. The medical deviceof claim 1, wherein each of the plurality of prongs extends radiallyoutwardly from the connecting segment, and wherein the curvature in thefirst direction is defined between the connecting segment and acorresponding free end of the corresponding prong.
 7. The medical deviceof claim 1, wherein the at least one biomaterial cover is coupled to theat least one of the proximal and distal discs by the one or moresutures.
 8. The medical device of claim 7, wherein the one or moresutures comprise one or more bioabsorbable sutures.
 9. The medicaldevice of claim 1, wherein the at least one biomaterial cover includes aproximal biomaterial cover defining a first cavity and a distalbiomaterial cover defining a second cavity, wherein the proximal disc ispositioned within the first cavity and the distal disc is positionedwithin the second cavity.
 10. The medical device of claim 9, wherein theproximal and distal biomaterial covers are coupled together.
 11. Aretrieval system for recapturing a medical device at a target site, theretrieval system comprising: a medical device comprising: a frame havingproximal and distal ends, the frame comprising a proximal disc at theproximal end, a distal disc at the distal end, and a connecting segmenthaving a proximal end and a distal end connecting the proximal anddistal discs, each of the proximal and distal discs include a respectiveplurality of prongs having a curvature in a first direction, each of theproximal and distal discs having a maximum cross-sectional dimensionlarger than the connecting segment; and at least one biomaterial cover,the at least one biomaterial cover comprising an outer section and aninner section defining a cavity therebetween, wherein at least one ofthe proximal and distal discs of the frame is positioned in the cavity,the at least one biomaterial cover further comprising a plurality ofpockets corresponding to the plurality of prongs, wherein the pluralityof prongs enable (1) de-coupling of the frame from the at least onebiomaterial cover when the plurality of prongs are withdrawn from theplurality of pockets of the at least one biomaterial cover by rotationof the plurality of prongs in a second direction opposite the firstdirection after the medical device is fully deployed at the target siteand (2) withdrawal of the frame from the target site; and a retrievaldevice comprising: a retrieval catheter; a recapture cable within theretrieval catheter and translatable with respect to the retrievalcatheter; and a coupling member configured to couple the medical deviceto the recapture cable for rotation of the frame relative to the atleast one biomaterial cover and withdrawal of the frame from the atleast one biomaterial cover after endothelialization over the medicaldevice at the target site has occurred.
 12. The retrieval system ofclaim 11, wherein the distal end of the retrieval catheter comprises adocking cap.
 13. The retrieval system of claim 12, wherein a proximalend of the connecting segment of the medical device comprises aconnecting member, and wherein the docking cap has a non-circular shapecomplementary to a shape of the connecting member.
 14. The retrievalsystem of claim 13, wherein each of the plurality of prongs extendsradially outwardly from the connecting segment, and wherein thecurvature in the first direction is defined between the connectingsegment and a corresponding free end of the corresponding prong.
 15. Theretrieval system of claim 14, wherein the recapture cable is configuredto be rotated in the second direction opposite to the first direction towithdraw the plurality of prongs from the at least one biomaterialcover.
 16. A method of recapturing a device frame deployed at a targetsite, the method comprising: locating a medical device at the targetsite, the medical device including a frame having proximal and distalends, the frame including a proximal disc at the proximal end, a distaldisc at the distal end, and a connecting segment having a proximal endand a distal end connecting the proximal and distal discs, each of theproximal and distal discs including a respective plurality of prongshaving a curvature in a first direction, each of the proximal and distaldiscs having a maximum cross-sectional dimension larger than theconnecting segment, the medical device further including at least onebiomaterial cover including an outer section and an inner sectiondefining a cavity therebetween, wherein at least one of the proximal anddistal discs of the frame is positioned in the cavity, the at least onebiomaterial cover further comprising a plurality of pocketscorresponding to the plurality of prongs, wherein the plurality ofprongs enable (1) de-coupling of the frame from the at least onebiomaterial cover when the plurality of prongs are withdrawn from theplurality of pockets of the at least one biomaterial cover by rotationof the plurality of prongs in a second direction opposite the firstdirection after the medical device is fully deployed at the target siteand (2) withdrawal of the frame from the target site; deploying themedical device in an expanded configuration at the target site; after athreshold amount of endothelialization over the medical device hasoccurred, coupling a cable to the frame of the medical device; rotatingthe cable to constrict the plurality of prongs of the frame; andwithdrawing the frame from the at least one biomaterial cover at thetarget site.
 17. The method of claim 16, wherein said coupling the cableto the frame of the medical device comprises: attaching a couplingmember at a distal end of the cable to a connecting member at a proximalend of the frame.
 18. The method of claim 17, wherein said attachingcomprises looping the coupling member around the connecting member. 19.The method of claim 18, wherein each of the plurality of prongs extendsradially outwardly from the connecting segment, and wherein thecurvature in the first direction is defined between the connectingsegment and a corresponding free end of the corresponding prong, andwherein said rotating comprises rotating the cable in the seconddirection opposite to the first direction to withdraw the plurality ofprongs from the at least one biomaterial cover.